/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.iotdb.tsfile.write.schema;

import org.apache.iotdb.tsfile.common.conf.TSFileDescriptor;
import org.apache.iotdb.tsfile.encoding.encoder.Encoder;
import org.apache.iotdb.tsfile.encoding.encoder.TSEncodingBuilder;
import org.apache.iotdb.tsfile.file.metadata.enums.CompressionType;
import org.apache.iotdb.tsfile.file.metadata.enums.TSDataType;
import org.apache.iotdb.tsfile.file.metadata.enums.TSEncoding;
import org.apache.iotdb.tsfile.utils.ReadWriteIOUtils;
import org.apache.iotdb.tsfile.utils.StringContainer;

import java.io.IOException;
import java.io.OutputStream;
import java.io.Serializable;
import java.nio.ByteBuffer;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;

/**
 * TimeseriesSchema is like MeasurementSchema, but instead of measurementId, it stores the full
 * path.
 */
public class TimeseriesSchema implements Comparable<TimeseriesSchema>, Serializable {
    private String fullPath;
    private TSDataType type;
    private TSEncoding encoding;
    private transient TSEncodingBuilder encodingConverter;
    private CompressionType compressor;
    private Map<String, String> props = new HashMap<>();

    public TimeseriesSchema() {
    }

    public TimeseriesSchema(String fullPath, TSDataType tsDataType) {
        this(
                fullPath,
                tsDataType,
                TSEncoding.valueOf(TSFileDescriptor.getInstance().getConfig().getValueEncoder()),
                TSFileDescriptor.getInstance().getConfig().getCompressor(),
                Collections.emptyMap());
    }

    /**
     * set properties as an empty Map.
     */
    public TimeseriesSchema(String fullPath, TSDataType type, TSEncoding encoding) {
        this(
                fullPath,
                type,
                encoding,
                TSFileDescriptor.getInstance().getConfig().getCompressor(),
                Collections.emptyMap());
    }

    public TimeseriesSchema(
            String fullPath, TSDataType type, TSEncoding encoding, CompressionType compressionType) {
        this(fullPath, type, encoding, compressionType, Collections.emptyMap());
    }

    /**
     * Constructor of TimeseriesSchema.
     *
     * <p>props - information in encoding method. For RLE, Encoder.MAX_POINT_NUMBER For PLAIN,
     * Encoder.maxStringLength
     */
    public TimeseriesSchema(
            String fullPath,
            TSDataType type,
            TSEncoding encoding,
            CompressionType compressionType,
            Map<String, String> props) {
        this.type = type;
        this.fullPath = fullPath;
        this.encoding = encoding;
        this.props = props == null ? Collections.emptyMap() : props;
        this.compressor = compressionType;
    }

    /**
     * function for deserializing data from byte buffer.
     */
    public static TimeseriesSchema deserializeFrom(ByteBuffer buffer) {
        TimeseriesSchema timeseriesSchema = new TimeseriesSchema();

        timeseriesSchema.fullPath = ReadWriteIOUtils.readString(buffer);

        timeseriesSchema.type = ReadWriteIOUtils.readDataType(buffer);

        timeseriesSchema.encoding = ReadWriteIOUtils.readEncoding(buffer);

        timeseriesSchema.compressor = ReadWriteIOUtils.readCompressionType(buffer);

        int size = ReadWriteIOUtils.readInt(buffer);
        if (size > 0) {
            timeseriesSchema.props = new HashMap<>();
            String key;
            String value;
            for (int i = 0; i < size; i++) {
                key = ReadWriteIOUtils.readString(buffer);
                value = ReadWriteIOUtils.readString(buffer);
                timeseriesSchema.props.put(key, value);
            }
        }

        return timeseriesSchema;
    }

    public String getFullPath() {
        return fullPath;
    }

    public void setFullPath(String fullPath) {
        this.fullPath = fullPath;
    }

    public Map<String, String> getProps() {
        return props;
    }

    public TSEncoding getEncodingType() {
        return encoding;
    }

    public TSDataType getType() {
        return type;
    }

    public void setProps(Map<String, String> props) {
        this.props = props;
    }

    /**
     * function for getting time encoder.
     */
    public Encoder getTimeEncoder() {
        TSEncoding timeEncoding =
                TSEncoding.valueOf(TSFileDescriptor.getInstance().getConfig().getTimeEncoder());
        TSDataType timeType = TSFileDescriptor.getInstance().getConfig().getTimeSeriesDataType();
        return TSEncodingBuilder.getEncodingBuilder(timeEncoding).getEncoder(timeType);
    }

    /**
     * get Encoder of value from encodingConverter by measurementID and data type.
     *
     * @return Encoder for value
     */
    public Encoder getValueEncoder() {
        // it is ok even if encodingConverter is constructed two instances for concurrent scenario
        if (encodingConverter == null) {
            // initialize TSEncoding. e.g. set max error for PLA and SDT
            encodingConverter = TSEncodingBuilder.getEncodingBuilder(encoding);
            encodingConverter.initFromProps(props);
        }
        return encodingConverter.getEncoder(type);
    }

    public CompressionType getCompressor() {
        return compressor;
    }

    /**
     * function for serializing data to output stream.
     */
    public int serializeTo(OutputStream outputStream) throws IOException {
        int byteLen = 0;

        byteLen += ReadWriteIOUtils.write(fullPath, outputStream);

        byteLen += ReadWriteIOUtils.write(type, outputStream);

        byteLen += ReadWriteIOUtils.write(encoding, outputStream);

        byteLen += ReadWriteIOUtils.write(compressor, outputStream);

        if (props == null) {
            byteLen += ReadWriteIOUtils.write(0, outputStream);
        } else {
            byteLen += ReadWriteIOUtils.write(props.size(), outputStream);
            for (Map.Entry<String, String> entry : props.entrySet()) {
                byteLen += ReadWriteIOUtils.write(entry.getKey(), outputStream);
                byteLen += ReadWriteIOUtils.write(entry.getValue(), outputStream);
            }
        }

        return byteLen;
    }

    /**
     * function for serializing data to byte buffer.
     */
    public int serializeTo(ByteBuffer buffer) {
        int byteLen = 0;

        byteLen += ReadWriteIOUtils.write(fullPath, buffer);

        byteLen += ReadWriteIOUtils.write(type, buffer);

        byteLen += ReadWriteIOUtils.write(encoding, buffer);

        byteLen += ReadWriteIOUtils.write(compressor, buffer);

        if (props == null) {
            byteLen += ReadWriteIOUtils.write(0, buffer);
        } else {
            byteLen += ReadWriteIOUtils.write(props.size(), buffer);
            for (Map.Entry<String, String> entry : props.entrySet()) {
                byteLen += ReadWriteIOUtils.write(entry.getKey(), buffer);
                byteLen += ReadWriteIOUtils.write(entry.getValue(), buffer);
            }
        }

        return byteLen;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        TimeseriesSchema that = (TimeseriesSchema) o;
        return type == that.type
                && encoding == that.encoding
                && Objects.equals(fullPath, that.fullPath)
                && Objects.equals(compressor, that.compressor);
    }

    @Override
    public int hashCode() {
        return Objects.hash(type, encoding, fullPath, compressor);
    }

    /**
     * compare by full path.
     */
    @Override
    public int compareTo(TimeseriesSchema o) {
        if (equals(o)) {
            return 0;
        } else {
            return this.fullPath.compareTo(o.fullPath);
        }
    }

    @Override
    public String toString() {
        StringContainer sc = new StringContainer("");
        sc.addTail(
                "[",
                fullPath,
                ",",
                type.toString(),
                ",",
                encoding.toString(),
                ",",
                props.toString(),
                ",",
                compressor.toString());
        sc.addTail("]");
        return sc.toString();
    }
}
